The ability to carry light from within a sealed enclosure to an illumination target is typically accomplished using a simple window or fiber optic coupler. However, these measures do not suffice to make the light source enclosure and the optical delivery means separable, and nominally hermetically sealed once joined, such as may be desired in an implantable medical device. Such implantable medical devices may be of use in photomedical and optogenetic therapies. Such systems are also described in International Appl. No. PCT/US2013/000262, which shares at least one inventor in common with the present application, and is hereby incorporated by reference in its entirety.